}

type http2pipeBuffer interface {
	Len() int
	io.Writer
	io.Reader
}

// setBuffer initializes the pipe buffer.
// It has no effect if the pipe is already closed.
func (p *http2pipe) setBuffer(b http2pipeBuffer) {
	p.mu.Lock()
	defer p.mu.Unlock()
	if p.err != nil || p.breakErr != nil {
		return
	}
	p.b = b
}